Adjustable self-balancing excavating apparatus



July 10, 1956 w. THOMAS ADJUSTABLE SELF-BALANCING EXCAVATING APPARATUS Filed July 17, 1953 4 Sheets-Sheet 1 INVENTOR I ViZZiam Th0 mas TTORNEY July 10, 1956 w. THOMAS 2,753,637

ADJUSTABLE SELF-BALANCING EXCAVATING APPARATUS 9 54 65 60 ii I I INVENTOR William Thomas July 10, 1956 w. THOMAS 2,753,537

ADJUSTABLE SELF-BALANCING EXCAVATING APPARATUS Filed July 17, 1953 4 Sheets-Sheet 3 i 60 INVENTOR William Tham 0/5 TTORNEY W. THOMAS July 10, 1956 ADJUSTABLE SELF-BALANCING EXCAVATING APPARATUS Filed July 17, 1953 4 Sheets-Shae. 4

INVENTOR A ORNEY United States Patent ADJUSTABLE SELF-BALAN ClN G EXCAVATING APPARATUS William Thomas, South San Francisco, Calif.

Application July 17, 1953, Serial No. 368,788

11 Claims. (CI. 3788) This invention relates to an improved adjustable, selfbalancing excavating or digging apparatus and has for its primary object to provide an excavating apparatus of a portable type which will be self-balancing in operation to produce a minimum of strain on the apparatus and on a portable support by which the apparatus is carried and wherein the excavating unit is so constructed that the excavated material is thrown inwardly of the unit, rather than outwardly thereof, thereby more equally distributing the weight of the apparatus relatively to a vehicle on which the apparatus is mounted.

Among the primary objects of the present invention is to provide an improvement of the excavating apparatuses as disclosed by my prior patents, Nos. 2,405,622 and 2,636,288 whereby strains on the apparatus will be matcrially reduced thereby providing an excavating apparatus which may be operated with much greater safety and without risk of the vehicle on which the apparatus is supported being overturned by operation of the apparatus.

More particularly, it is an aim of the present invention to provide an excavator of the endless conveyor type equipped with a reciprocating digger which accomplishes a digging operation in both directions of its movement, in addition to the digging operation accomplished by buckets of the endless conveyor, and whereby the digging buckets of the endless conveyor receive the material excavated by the reciprocating digger.

Still a further object of the invention is to provide an excavating apparatus having novel means for readily freeing the excavator after one or more of the digging units have become fouled or stuck on rock or other solid formation.

Still a further object of the invention is to provide an excavating unit wherein a simultaneous push and pull is exerted by opposite moving portions of the unit and which results in a counteracting of forces to minimize the strains imparted from the unit to a supporting vehicle thereof.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, illustrating presently preferred embodiments thereof, and wherein:

Figure l is a side elevational view, partly broken away, of the improved excavating apparatus;

Figure 2 is a fragmentary top plan view thereof, on an enlarged scale;

Figure 3 is an enlarged longitudinal sectional view taken substantially along a plane as indicated by the line 3-3 of Figure 2;

Figure 4 is an enlarged cross sectional view of the excavating unit, taken substantially along a plane as indicated by the line 4-4 of Figure 3;

Figure 5 is a fragmentary longitudinal sectional view, partly in side elevation, of a portion of the digging apparatus, with certain of the parts omitted, and illustrating a modified form of the reciprocating digger;

Figure 6 is a fragmentary bottom plan view of the reciprocating digger, as illustrated in Figures 1 to 4;

Figure 7 is a cross sectional view of the digger, taken 2,753,637 Patented July 11 1956 substantially along a plane as indicated by the line 7--7 of Figure 6;

Figure 8 is a fragmentary side elevational view of a modified form of the excavating apparatus, and

Figure 9 is a view similar to Figure 8 of another modified form of the excavating apparatus.

Referring more specifically to the drawings, the improved adjustable, counterbalancing excavator or digger in its entirety and as illustrated in Figures 1 to 4, 6 and 7 is designated generally 12 and includes a supporting vehicle 13 which may be of any suitable type, either selfpropelled or trailer type. While the vehicle 13 is shown in Figure 1 as being provided with ground wheels 14, said vehicle 13 could be equipped with track engaging wheels, could be supported on runners or could be in the form of a watercraft or boat. The vehicle 13 preferably includes a bed 15 on which is fixed a bottom plate or disk 16. A turntable 17 is turnably mounted on the vehicle 13 about a center shaft or axle 18 thereof and is supported for free rotation above the disk or plate 16 by a plurality of antifriction ball bearings 19. The turntable 17 may be suitably rotated either by power, in any suitable manner, or manually and may be retained against rotation in any position of adjustment by a removable headed pin 20 which extends downwardly through the turntable 17 and which selectively engages openings, not shown in the disk 16.

A shaft 21 is journalled above a portion of the turntable 17 in a pair of aligned bearings 22, which are fixed to and rise from said turntable adjacent: a portion of the periphery thereof. Any suitable form of prime mover 23 may be secured on the turntable 17 for driving the shaft 21 through a pair of sprocket wheels 24 and an endless chain 25 which is trained over said sprocket wheels. One of the sprocket wheels 24 is keyed to the shaft 21 and the other sprocket wheel is fixed to a drive shaft 26 of the motor or engine 23.

A pair of corresponding supporting plates 27 are pivotally mounted on the shaft 21 between pairs of collars 28 which are suitably fixed detachably to the shaft 21. A pair of hydraulic cylinders 23 have closed ends which are pivotally connected to brackets 30 which are fixed to and rise from the turntable 17, remote from the shaft 21. The hydraulic cylinders 29 are mounted for swinging movement in vertical planes on the brackets 3t! and each contain a piston, not shown, having a connecting rod 31 extending therefrom reciprocably through the opposite free end of the cylinder 29. The outer ends of the connecting rods 31 are pivotally connected at 32 to the plates 27 at points spaced from and above the shaft 21. The hydraulic cylinders 29 are of a conventional double-acting type having feed and return conduits 33 and 34 co1nrnunicating with said cylinders adjacent each of the ends thereof for forcibly moving the connecting rods 31 either inwardly or outwardly of the cylinders 29.

An elongated beam 35 extends between the plates 27 and is connected thereto by a pair of rods 36 and 37 which extend through the beam 35 and are supported at their ends by the plates 27. The rods 36 and 37 are equally spaced from the shaft 21 and spaced outwardly with respect thereto. A shaft 38 extends rotatably through the plates 27 and the beam 35 and is preferably disposed between and in alignment with the rods 36 and 37. Sprocket wheels 39 are fixed to the ends of the shaft 38, outwardly of the plates 27 and in alignment with sprocket wheels 46 which are fixed to the ends of the shaft 21. The aligned sprocket wheels 39 and 40 are connected by endless chains 41 for driving the shaft 38 from the shaft 21.

The beam 35 has a shaft 42 extending transversely through and journalled in the upper or inner end thereof and a shaft 43 extends transversely through and is journalled in the outer or lower end of said beam, which is disposed remote to the plates 27. The shafts 42 and 43 each have a pair of sprocket wheels 44 fixed thereto and disposed on opposite sides of the beam 35. The sprocket wheels 44 of the shafts 42 and 43 which are located on corresponding sides of the beam 35 are connected by endless conveyor chains 45. The shaft 42 is also provided with an outer sprocket wheel 46 which is connected by an endless chain 47 to a sprocket wheel 48 which is fixed to the shaft 38. A plurality of corresponding conveying and digging buckets 49 are fixed to the conveyor chains 45 and extend therebetween, said buckets .49 being disposed in longitudinally spaced relationship to one another relatively to the chains 45. The buckets '49 have open leading ends 50 and outer walls 51 which are preferably provided with teeth 52 which project from the open ends 50 of the buckets, as best illustrated in Figure The endless conveyor 45, 49 is driven in a direction as indicated by the arrow 90 in Figure 1 so that the bottom flight thereof travels downwardly and the top 'fiight travels upwardly.

A digger, designated generally 53, is reciprocably supported by the conveyor beam 35 between the outer or lower end thereof and the plates 27 and comprises an elongated body member of channel-shaped cross section having side walls 54, as best seen in Figure 7, which "loosely straddle the lower portion of theendless conveyor and which are provided with aligned elongated slots 55. A plurality of supporting rods '56 extend transversely through the beam 35 in longitudinally spaced relationship to one another and project outwardly from Opposite sides of said beam loosely through said slots 55. The rods 56 are spaced relatively to one another 'to engage corresponding portions of the slots 55 for supporting'the digging member on the lower or outer portion of the beam "35 and for sliding movement longitudinally thereof. The bottom 57 of the digging member 53 is disposed below and spaced from the beam 35 and is provided with longitudinally spaced struck-down and laterally flared scoop portions 58 forming'openings 59 in the bottom '57 between the scoops 58 and the interior of the channel shaped body portion. One of said scoops 58 is disposed at the upperend of the digger 53, as best illustrated .in Figure 3. The scoops 58 are provided with digging teeth '60 which are secured to the outer sides of the bottom and side walls of said scoops 58 and which project upwardly from the open upper ends of the scoops. The reciprocating digger'53 is also provided with a scoop '61 at its'lower end which-extends in the opposite direction to the scoops 58 and which is flared downwardly and outwardly away from the endless conveyor 45, 49 and whichis also laterally flared,'as best illustrated in Figure 6.

A rod-62 extends between and is anchored at its ends in the plates 27 outwardly of the rods 36 and 37. A pair of brace bars 63 are attached at corresponding ends thereof to 'the'rod 62 and have their opposite ends attached to one of the cross rods 56, outwardly of the digger 53. The bars 63 provide braces for additionally supporting theouter .or longer end of the endless conveyor andthe digger 53 which is mounted thereon.

The closed ends of'a pair .of double-acting hydraulic cylinders "'64 are pivotally mounted on the rod'36 on Q1 positesides of the beam 35 and containpistons, not shown, having piston rods 65 extending outwardly from the'opposite, free" ends of the cylinders64 and which are pivotally connected at'66 to the side walls 54 of the digger-53, at'the upper "end of said digger. The cylinders'64 each'has a combination supply andreturn con.- duit 67 communicating with the interior thereo'fadjacent its closed 'end and asimilar conduit 68 communicating with'said'cylinder adjacent its outer free end.

A-bucketsupporting bar 69 has oneend thereof suitably secured to the inner side of the upper portionof the digger bottom'57. The bucket supporting'bar 69 extends upwardly from the digger SS'beneath the end- 4 less conveyor 45, 49 to adjacent the upper end thereof and said bar is provided with an outwardly curved upper end 70. The bar 69 is relatively resilient for yielding movement downwardly and away from its position of Figure l beneath the endless conveyor 45, 49.

A post 71 may be detachably supported on the turntable 17 to provide a support for a portion of a sluice box 72, a part of which sluice box is disposed directly beneath the upper end of the endless conveyor '45 49. A receptacle 74 may :be seen-red on the turntable 17 at a point substantially diametrically opposite to the shaft 21. The receptacle 74 is adapted to contain weights and to cooperate with the engine or motor 23 for counterbalancing the weight of the plates 27 and parts supported thereby.

From the foregoing it will be readily apparent that the turntable 17 may be rotated to position the endless conveyor 45, 49 in any desired position relatively to the supporting vehicle 13 and with the sluice box 72 removed, the endless conveyor may be swung to a horizontal position for transportation by supplying a hydraulic medium under pressure in any suitable manner to -the outer ends of the cylinders 29 through the conduits 33 for drawing the piston rods 3-1 inwardly of said cylinders to swing the supporting members 27 upwardly and forwardly to substantially upright positions. Conversely, the

medium under pressure can be released from the outer ends of the cylinders 29 through the conduits 33 to allow the supporting plates 27 to swing outwardly anddownwardly to position'the endless conveyor45, 49 in a downwardly and rearwardly inclined position. If desirable or necessary, the hydraulic medium under pressure can be supplied to the inner or closed ends of-the cylinders 29through the conduits 34 for forcing the piston rods 31 outwardly'to swing the lower end of the endless conveyor downwardly for initially digging a trench 73 as illustrated in Figure l, of a desired depth or for maintaining the endless conveyor at a desired angle for maintaining the trench 73 of a desired depth as it is dug by the excavator. However, in most instances after the trench has been initially dug to a desired depth it is no longer necessary to maintain pressure in either end of the cylinders 29 as the weight of the endless conveyor will maintain it at a proper angle as illustrated in "Figure l, or a slight pressure may be maintained in either the inner or outer ends of said cylinders 29 to insure that a trench of uniform depth will be dug. It will thus be obvious that should the excavator strike a rock formation or other 0bstruction that it can readily swing upwardly to avoid'be'ing damaged thereby.

As previously stated, the endless conveyor 45, 49 is driven in a direction as indicated by the arrow 9!) in Figure l'by the chain 47 driven from the shaft'38 which is in turn driven from the shaft 21'by the sprocket wheels 39 and 40 and chains 41. The shaft 21 is in turn driven fromthe motor or engine shaft 26 by the sprocket wheels 24 and chain 25. The sizes of the various sprocket wheels may be varied as desired to accomplish the necessary or desired speed reduction between the shaft 26 and the endless conveyor shaft 42.

Simultaneously with the operation of the endless conveyor, the hydraulic medium under pressure from any suitable source and by any suitable control, notshown, is alternately supplied to the closed ends and ,freeends of the double-acting hydraulic cylinders 64 through the conduits 67 and 68 and alternately withdrawn or returned from the cylinder ends through the same conduits, to cause the piston rods 65 to slide inwardly an'd. outwardly through the cylinders 64 toreciprocate the digger 53 relatively to the endless conveyor. The digger 53 .is supportedbyxthe side wall slots thereof engaging the rods 56-and said slots. allow the digger 5.3 to slide relatively to the rods and endless conveyor longitudinally of said endless. sn v rn h u st k r t one 5 41? teeth dig ,or cut. into the .walls 731; of the trench 7,31and grasps? the material dug thereby is picked up by the scoops 58 and directed into the channel of the digger through the openings 59 to be picked up by the downwardly traveling buckets 49 of the bottom flight of the endless conveyor, which are traveling through the bottom portion of the digger 53 between its bottom 57 and the beam 35. After the buckets 49 leave the lower end of the digger 53 the teeth 52 thereof will execute a digging operation when passing around the lower sprocket wheels 44. On the downstroke of the digger 53 the bottom scoop 61 will scrape the ditch wall 73a for executing a cutting operation and the material scraped by said bottom scoop 61 will likewise be picked up by the downwardly traveling buckets 49. After the buckets 49 have passed around the bottom sprocket wheels 44, said buckets will move upwardly along the upper flight of the endless conveyor and over the upper sprocket wheels 44 and in so moving the buckets 49 will be inverted and the dirt carried thereby discharged downwardly into the sluice box 72 disposed therebeneath. However, the buckets in passing over the upper sprocket wheels 44 may be caused to discharge onto a suitable conveyor supported by the turntable 17 in lieu of the sluice box 72 and from which the material may be discharged at any location desired.

After the buckets 49 have passed around the upper sprocket wheels 44 and executed the dumping operation, previously described, the open leading ends of the buckets will engage the outwardly turned end 70 of the bucket support 69 and will thereafter travel between said bucket support and the beam 35 to prevent the chains from sagging downwardly to insure that the buckets 49 will readily enter the open upper end of the digger 53. It will be obvious that the digger 53 may be of any desired length or several corresponding diggers could be employed and connected in tandem by suitable connecting links.

Figure illustrates a slightly modified form of digger designated generally 53a and differing from the digger 53 only in that the digger 53a is provided with a top wall 57a corresponding to the bottom wall 57a thereof and to the bottom wall 57 of the digger 53. The top and bottom walls 57a of the digger 5311 are provided with scoops 58a, openings 59a and teeth 60m, corresponding to the scoops, openings and teeth of the digger 53. After the scoops 58a, teeth 60a and the bottom scoop 61a of the bottom or lowermost wall 57a have become worn, the digger 53a may be removed and inverted to position the top wall 57a in a bottommost position and so that its scoops 58a and 61a and teeth 60a will then be disposed in a digging position. The digger 53a is mounted in the same manner as the digger 53 and is likewise reciprocated in the same manner, as previously described in detail.

Figure 8 illustrates a slightly modified form of the excavator and which differs from the excavator in Figures 1 to 4, 6 and 7 in that a driven shaft 36a is substituted for the rod 36 and may be driven in any suitable manner as by sprocket wheels 75 which mesh with the chains 45. The driven shaft 36a is provided with cranks 76 to which complementary ends of links 77 are pivotally connected by the pins 78 of said cranks. The opposite ends of the links 77 are connected to the upper ends of the side walls 54 of the digger 53 by the pivot pins 66. The cranks 76 and links 77 replace the hydraulic cylinders 64 and piston rods 65 and are driven by the chains 45 to impart reciprocating motion to the digger 53.

Likewise, the brace bars 63 are omitted from the excavating apparatus as illustrated in Figure 8 and in lieu thereof a brace bar 79 is provided which is connected at one end to the rod 62 and which is provided with hanger braces or links 88 which are pivotally connected thereto and to the upper and intermediate supporting rods 56. A diagonal brace rod 81 extends from the connection of the upper link 88 with the brace bar 79 to the intermediate supporting rod 56 to which the lower link 80 is connected. A double-acting hydraulic ram 82 is attached to the lower end of the bar 79 and the head 83 of said rain is projected outwardly of the ram cylinder 84 by a hydraulic medium supplied to the inner end of the ram cylinder through a conduit 35, as the digger 53 is displaced upwardly, to counteract any downward thrust of the excavator, by engagement of the ram cylinder head with the bottom of the trench 73. The ram head 83 can be retractedby a hydraulic medium supplied through the conduit 86 to the outer end of the cylinder 84 as the digger 53 is displaced downwardly.

Figure 9 illustrates another modification wherein the digger 53 is reciprocated by a double-acting hydraulic cylinder in the same manner as illustrated in Figures 1 to 4 and 6 to 7. The structure of Figure 9 otherwise differs from that of. Figure 8 in that an openwork beam structure 87 is provided in lieu of the brace bar 79 and said beam structure is connected by links a to the upper and lowermost supporting rods 56. A diagonal brace 81a extends between the connection of the upper link 80a to the beam structure 87 and the lower rod 56. The beam structure 87 is supported at its upper end on the rod 62 and is additionally supported relatively to the plates 27 by diagonal braces 88 extending between the rod 36 and a portion of the beam structure 87 which is spaced from the rod 62. A hydraulic ram 82a, corresponding to the ram 82 and for accomplishing the same result, is secured to and extends from the lower outer end of the beam structure 87.

In view of the detailed description of the operation of the adjustable excavating apparatus as illustrated in Figures 1 to 4, 6 and 7, a further description of the modified forms thereof as illustrated in Figures 8 and 9, is considered unnecessary.

Various other modifications and changes are likewise contemplated and may obviously be resorted to, without departing from the spirit or scope of the invention as hereinafter defined by the appended claims.

. I claim as my invention:

1. An apparatus of the character described comprising a base structure, an elongated endless conveyor including a plurality of longitudinally spaced digging buckets, means mounted on the base structure and adjustably supporting said endless conveyor in an inclined position with an outer end thereof in a lowered digging position, driving means supported by the base structure and connected to and driving said endless conveyor in a direction to cause a bottom flight thereof to travel downwardly, said endless conveyor including a frame, an elongated digger, means slidably supporting said digger on said endless conveyor frame adjacent the lower end of the endless conveyor and longitudinally thereof, said digger including a bottom provided with outwardly extending upwardly opening scoops disposed beneath the bottom flight of the endless conveyor, said bottom having openings therein communicating with said scoops for the passage of material dug by the scoops, and actuating means connected to said first mentioned means and to said digger for reciprocating the digger relatively to the endless conveyor, the buckets of the bottom flight of said endless conveyor traveling downwardly through the digger for receiving the material dug by the scoops and discharged therefrom through the openings in the digger bottom.

2. An apparatus as in claim 1, said scoops being laterally flared relatively to the digger and being of a width greater than the width of the digger.

3. An apparatus as in claim 1, said digger including a bottom scoop extending downwardly and outwardly from the lower end of the digger bottom and executing a digging stroke on the downward movement of the digger relatively to the endless conveyor, said bottom scoop terminating above the lower end of said endless conveyor.

4. An apparatus as in claim 1, said digger being of channel shape cross section and having side walls loosely straddling a portion of the endless conveyon rods projecting outwardly from opposite sides of said frame, said a s walls o the d gger having longitudinal y extend ng elongated slot loose y eng giug vs id ro s an z mhining therewith topro ide he m n s ar dably supp rting the diggeron theiendless Conveyor.

5. An apparatus as in claim 1, said digger actuating m ns tto llpr sing a fluid pressure operated cylinder con nected to saidfirstmentionedrneans and having a reciprocatingpiston rod extending outwardly fro-mono end .of said cylinder and connected to thedigger.

,6, apparatus as in claim 1, said digger actuating means oomprising a chankshaft connected to and driven by the vd iving m ans of saidendlfisscon eyo d a nnecting rod connected to a crank of said crankshaft and to .said dig er- An a para us a in (claim said di cluding a top wall correspond ng to thet igger bottom, vsaid dig being detachab y unted n erchangeably 0n e dl conveyor With either the rbottomtor top wall thereof disposed vbelow a portion ofthe vbottom flight of the endless CQII YQ 8. An apparatus as intclaim 1, a beam structure sup- Ported y said first mention means above an l ngitudina ly of the lower portion of said endless conveyor; and hanger means depending from said beam structure and connected to the digger supporting means for supporting the lower outerendiof the endless conveyor.

9. An apparatus as in claim 8, and ram means c.01 nected to and extendingfrom a lower outer end of said beam structure for counteracting the downward thrust on aidqcndless .0nvey or resulting from the upward movemerit of ,the digger on the digging stroke thereof, and means projecting said ram outwardly and downwardly of the endless conveyor as said digger isrnoved upwardly.

1.0. An apparatuses in claim 1, a guide member fixed to said digger and extendingfrom the upper end thereof and disposed below the upper portion of the bottom flight of said endless conveyor for supporting and guiding the buckets of the bottom flight of the endless conveyor in thei downward movemen int the .unne end of di er- :111. Anexeaitatore harac r desc be routr ns ahase structure, ntelongated endles onveyor nch; he a PltrraliW of longitud nally spaced buckets, mean .ntoun d ion th base structure and upporting s id endl s .convey for swinging m vemen in a hor zontal p an relative to the \basetstn t re, a se on mean on e t d o ai s mentioned mean for win ing the endles coh ey r ina vertical p aner lative to the b se struc ure, aid .entl e s eyor being no mally dispose in an inlin t igging posi io aa lh ihgla lower dig ngtend and an upper discharge end, driving means mounted on the base...s. rn thr.e a d c nnec e toand drivi g aid ndess conveyor in a vdire ion us a bQ- tomvflight ther o l o travel downwardly, said en les .c nv yo tincludihg a f ame, a eh nnelshapctl elo gate digger, mean supporting said .channe shapeddig ert n aport ontof the ow r p i said end es onv yo fr m a in a P. sit on w ereby t e bot om i vvof sa d e l ssreonveyor ra l lon dina y thereth'ro gh, said igg r having a t o p vide with a plu alityof downwardly and upar y facing d ggin scoops-teach op n nsinto sa d s and means nnected to s idfirs mentioned mean nd digger for vimparting a re pr ng m t on t h digger, th trnaterialrdug by said scQOPS eing disch rg d vinto the diggenandtinto the buckets :ofthe bottom :flight of the endless conveyor traveling downwardly through said-digger.

keiereri s fli d n th [11. of thi pa en UNITED STATES PATENTS 

